The use of computers, especially personal computers (PCs) is widespread. A PC includes a number of individual components, such as a microprocessor, memory modules, various system and bus control units, and a wide variety of data input/output (I/O) devices. The components included in a PC require electrical power for operation, and a significant amount of energy is wasted when the PC is not used while maintained in a powered-up state. This is particularly disadvantageous for portable notebook computers, which rely on batteries for power. In order to provide more energy-efficient PCs, power management techniques and circuitry have been developed which place the PC into one or more powered-down states at appropriate times. For example, a PC can successively enter states or modes of progressively lower power consumption until a user interaction or other selected event occurs. Typical portable computers have states such as Full-On, Standby, Suspend, and Off.
Many portable computers include an optical status indicator with a light-emitting diode (LED) to indicate a current power-consumption status. Typically, the LED provides a constant intensity optical signal (as seen by the user) when the computer is in a Full-On state, and the LED emits no light when the computer is Off. When the computer is operating in one of the powered-down states, such as Standby or Suspend, the LED flashes off and on. The flashing LED can be aesthetically irritating to some users, and does not provide information indicating in which of the various powered-down states the computer currently operates.